Department of Applied Biology and Research Institute of Life Science, Gyeongsang National University, Jinju, 660-701, South Korea.
Planta. 2010 Nov;232(6):1355-70. doi: 10.1007/s00425-010-1259-x. Epub 2010 Sep 4.
Plant root-associated bacteria (rhizobacteria) elicit plant basal immunity referred to as induced systemic resistance (ISR) against multiple pathogens. Among multi-bacterial determinants involving such ISR, the induction of ISR and promotion of growth by bacterial volatile compounds was previously reported. To exploit global de novo expression of plant proteins by bacterial volatiles, proteomic analysis was performed after exposure of Arabidopsis plants to the rhizobacterium Bacillus subtilis GB03. Ethylene biosynthesis enzymes were significantly up-regulated. Analysis by quantitative reverse transcriptase polymerase chain reaction confirmed that ethylene biosynthesis-related genes SAM-2, ACS4, ACS12, and ACO2 as well as ethylene response genes, ERF1, GST2, and CHIB were up-regulated by the exposure to bacterial volatiles. More interestingly, the emission of bacterial volatiles significantly up-regulated both key defense mechanisms mediated by jasmonic acid and salicylic acid signaling pathways. In addition, high accumulation of antioxidant proteins also provided evidence of decreased sensitivity to reactive oxygen species during the elicitation of ISR by bacterial volatiles. The present results suggest that the proteomic analysis of plant defense responses in bacterial volatile-mediated ISR can reveal the mechanisms of plant basal defenses orchestrated by endogenous ethylene production pathways and the generation of reactive oxygen species.
植物根际相关细菌（根际细菌）会引发植物基础免疫，即被称为诱导系统抗性（ISR），以抵抗多种病原体。在涉及这种 ISR 的多种细菌决定因素中，先前已经报道了细菌挥发性化合物对 ISR 的诱导和生长的促进作用。为了利用细菌挥发物对植物蛋白质进行全球从头表达的开发，在将拟南芥暴露于根际细菌枯草芽孢杆菌 GB03 后进行了蛋白质组分析。乙烯生物合成酶显著上调。通过定量逆转录聚合酶链反应的分析证实，乙烯生物合成相关基因 SAM-2、ACS4、ACS12 和 ACO2 以及乙烯反应基因 ERF1、GST2 和 CHIB 被细菌挥发物的暴露所上调。更有趣的是，细菌挥发物的排放显著上调了由茉莉酸和水杨酸信号通路介导的两种关键防御机制。此外，抗氧化蛋白的大量积累也为细菌挥发物引发 ISR 时活性氧敏感性降低提供了证据。本研究结果表明，通过细菌挥发物介导的 ISR 对植物防御反应的蛋白质组分析可以揭示由内源性乙烯产生途径和活性氧产生协调的植物基础防御的机制。
